# BEGIN WordPress
RewriteEngine on
#
# Unless you have set a different RewriteBase preceding this
# point, you may delete or comment-out the following
# RewriteBase directive:
RewriteBase /
#
# if this request is for "/" or has already been rewritten to WP
RewriteCond $1 ^(index\.php)?$ [OR]
# or if request is for image, css, or js file
RewriteCond $1 \.(gif|jpg|css|js|ico)$ [NC,OR]
# or if URL resolves to existing file
RewriteCond %{REQUEST_FILENAME} -f [OR]
# or if URL resolves to existing directory
RewriteCond %{REQUEST_FILENAME} -d
# then skip the rewrite to WP
RewriteRule ^(.*)$ - [S=1]
# else rewrite the request to WP
RewriteRule . /index.php [L]
#
# END wordpress

http://www.canonicalseo.com/wordpress-performance-improvement/

Improving WordPress performance with changes to .htaccess

More efficient RewriteRule for Wordpress

wordpress

Apache